This invention relates to systems and methods for performing backup or archive operations on data. A system's or data's importance to an organization or user is often used as a determining factor in assigning the degree to which the data or systems are protected. Some forms of protection are as simple as keeping backup copies of systems and data (“backups”), while others make use of redundant systems with rapid failover capabilities to ensure functional continuity. Generally speaking, backup systems that provide rapid or near instant backup cost more than systems which provide slower backup methods. As a result, backup time for some users/data may take longer than the user would like. As undesirable as this may be for the user, the enterprise may not be willing to spend additional money on a faster backup system.
Another factor affecting backup times is the bandwidth of the connection between the protected system and the backup repository. High bandwidth connections such as those made over a wired LAN may be as much as 100 megabits per second (Mbps), 1 gigabits per second (Gbps), or more. At these speeds backup can be completed in hours or even minutes with the largest backup sets. The same is not true of lower bandwidth connections. Many remote offices and remote workers are connected to their headquarters via low-bandwidth connections, commonly 1 Mbps and 2 Mbps connections. At this low bandwidth, backup of commonly sized hard disk drives can take more than a day and sometimes weeks.
Mobile, remote, and home office workers have always presented a problem to traditional centralized backup and archive solutions. Remote office and home office workers are hampered by low-bandwidth connections to centralized data centers. Mobile workers are further hampered by their dynamic and non-persistent network connectivity. At low-bandwidth connection speeds, backup of commonly sized hard disk drives would take more than a day and sometimes weeks to complete. Dynamic and non-persistent network connectivity only extends the amount of time it would take to complete a backup.
Window of Opportunity solutions (backup solutions that backup by queuing multiple small data sets with suspend/resume support or solutions that use a single data set with suspend/resume support) have successfully demonstrated the ability to work within the confines of low-bandwidth and non-persistent connectivity to deliver centralized data protection solutions for mobile, remote and home office users. However, such solutions may take hours, days, or weeks to complete initial backup or backup where large amounts of new data have been created.
There exists a need to inexpensively and rapidly perform backup operations on data over any variety of connection speeds in order to adequately protect the system/user in as little time as possible. Due to cost considerations, this objective should be accomplished without increasing the speed or number of connections between the backup data and the system, or increasing the speed, performance, throughput, or number of processors and/or data storage devices.
There is a need, therefore, for an improved method, article of manufacture, and apparatus for performing backup operations on data.